Do you have an idea of the fabrics you're using? Sometimes the fabric dictates the pattern choice. To save time, maybe a precut -- charms, layer cake, jelly roll-- might be a good solution. The moda bakeshop has lots of quick and easy patterns particularly well-suited to pre-cuts.
One I find easy and quick, yet popular, is a pattern called Five and Dimes. Using 12 fat quarters and a coordinating print, you get a nice generous sized throw. The tagline is 5 minutes to select fabrics, 10 minutes to cut, and 15 to layout. It really is one that's doable in a day.
RST